Norpolycyclopentadiene monohydrohalides



Patented Aug. 14, .1945

UNITED "STATES. PATENT OFFICE NORPOLYCYCLOPENTADIENE MONO- HYDROHALIDES Herman A. Bruson, Philadelphia, Pa., assignor to The Rcsinous Products at Chemical Company, Philadelphia, Pa., a corporation of Delaware No Drawing. Application February 20, 1943, Serial No. 476,641

10 Claims.

,This invention relates to addition-rearrangement products of hydrogen halides and polycyclopentadienes and a method for their preparation.

Inaccordance with the disclosure of the presentapplication, which is a continuation-in-part of copending application Serial No. 434,219, filed March 11, 1942,-polymers of cyclopentadiene contaming two double bonds per molecule are reacted, in thepresence of water, with hydrogen halides other thanv hydrogen fluoride to form unsaturated hydrogen halide addition products with a.simultaneous molecular. rearrangement of the original polycyclopentadiene ring system to a norpolycyclopentadiene ring system, as hereinafter described.

Typical polycyclopentadienes which can be used for the purpose of this invention are, for example, dicyclopentadiene, tricyclopentadiene, tetracyclopentadiene, pentacyclopentadiene, and homologues thereof having two double bonds per molecule. Mixtures of such polycyclopentadienes may also be used, including isomers and mixtures of isomers. These polycyclopentadienes are crystalline solids obtainable by heating cyclopentadiene at 150?- C. in a closed vessel. They may be represented by the general formula:

C I H 1311\03/ cn wherein n is zero or a small integer, such as 1, 2, or 3. I have found that only one double bond of the two present in the above polycyclopentadienes reacts with hydrochloric acid, hydrobromic acid or hydricdic acid even when an excess of these acids is employed. Furthermore, I have found that the addition occurs on the double bond of the cycle having the endomethylene bridge, and that a simultaneous molecular rearrangement takes place in this ring.

For example, dicyclopentadiene reacts with the hydrogen halide (ID!) as follows:

CE: I CH on o{l cn on 5 i Q Hi x n- H CK C r In an analogous manner, .tricyclopentadiene reacts only on the double bond of the endomethylene cycle with simultaneous molecular rearrangement of the latter.

CH CH of cfi Similarly tetracyclopentadiene and pentacyclopentadiene add hydrogen halides to form addition-rearrangement products.

All of these addition-rearrangement products are new substances. In view of the fact that they are derived from polycyclopentadienes but possess a new and diflerent ring system, they are referred to herein for the sake of brevity as norpolycyclopentadiene derivatives.

tion, it being understood that the quantities used can be varied from equivalent proportions to an excess of either component and that for technical purposes commercial mixtures 01' polycyclopentadienes can be used. Parts given are by weight.

Example 1 A mixture oi 132 parts or dicyclopentadiene and 200 parts of concentrated hydrochloric acid was stirred rapidly at -70 C. for live hours. The product was washed. dried and distilled under reduced pressure. The nordicyclopentadiene monohydrochlorid'e distilled 102-104/10-12 mm. as a colorless oil in a yield of 147.5 parts, or 87.5% of the theoretical yield. Upon redistlllation, it boiled at 100-102'/11 mm. and possessed the following constants: its" 1.1121; n 1.5205.

I Example 2 Amixture of 132 parts of dicyclopentadiene and 838 parts of concentrated hydrobromic acid (48%) was stirred rapidly at 40 C. for three hours. The product was washed, dried, and dis- 7 tilled under reduced pressure. The nor-dicyclopentadiene monohydrobr'omide distilled at /2 mm. as a pale yellow oil in a yield 01 193 parts, or 90% oi theory. Upon redistillation, it boiled at 1i3-114'/11 mm.

Example 3 Example 4 A mixture or 132 parts of dicyclopentadiene and 870 parts of aqueous 20% hydrochloric acid was stirred rapidly at 6040 C. for five hours.

The product was mixed with toluene and washed thoroughly with water followed by soda solution.

The toluene solution was evaporated to a residual oil which was distilled at 11 mm. pressure. The product obtained was nordicyclopentadiene monohydrochloride, which distilled over at 96-105 in an amount oi 95 parts.

Example 5 Dry hydrogen chloride gas was passed rapidly into 132 grams of dicyclopentadiene heated to 60-80 C. under a reilux condenser attached to a "Pyrex" glass flask in subdued light for a period of live hours. There occurred an increase in weight of only one gram. v

Water (5' cc.) was then added and the passage of hydrogen chloride gas continued for live hours at the same temperature. This time, the weight increase amounted to 35 grams. The resulting dark oil was washed with water, taken up in toluene, washed again successively with dilute soda solution and water, and the toluene evaporated under reduced pressure on the steam bath.

The residual oil weighed 158 grams. Upon distillation in vacuo, it yielded grams or pure nordicyclopent adiene monohydrochloride'.

Example 6 A mixture consisting of 100 parts of tricyclepentadiene (mixed alpha and beta isomers) and assaos':

- Five hundred parts of dlcyclopentadiene was heated in a sealed vessel at C. for eight hours. A waxy solid was formed, which consisted essentially of dicyclopentadiene, tricyclopentadiene, tetracyclopentadiene, pentacyclopentadiene and higher polycyclopentadienes. This material was mixed with twice its weight of aqueous fuming hydrochloric acid and stirred rapidly at 100-110 C. for twelve hours. The oil layer was separated, washed, dried, and filtered while hot from any insoluble matter. The clear oil obtained was a mixture 01' the monohydrochlorides oi nor-di-, -tri-, -tetra-, and -pentacyclopentadiene. Upon distillation in vacuum, thev wherein X is a hologen such as chlorine, bromine, or iodine and n is a number from zero to a small whole number. It will be noted that the terminal cycle represented at the right of the formula con-' tains an oleflnic linkage which is capable of further reaction, as with chlorine, bromine, iodine, iodine chloride, thiocyanogen, hydrogen, etc.

The addition-rearrangement reaction of a crystalline polycyclopentadiene having. two double bonds and one to tour endomethylene cycles per molecule and a hydrogen halide having a molecular' weight above twenty is generically represented as follows:

.. s c Li wherein Call is a propenylene group which in conjunction with the adjoining carbon atoms forms a cyclopenteno group.

Although in the above examples practically pure polycyclopentadienes have been used, the process shown may also be applied to mixtures oi hydrocarbons which contain or more of the polycyclopentadienes having two double bonds per molecule, such as are obtained in the thermal cracking of petroleum or in the manufacture of water gas. The reaction of the polycyclopentadienes provides a new means for separating the components of mixtures of unsaturatedhydrocarbons and gives new utility to such products.

I claim:

1. An addition-rearrangement product of a hydrogen halide having a molecular weight above twenty and a crystalline polycyclopentadiene having two double bonds and one to four endomethylene cycles per molecule, said product being formed in the presence of water and being a norpolycyclopentadiene monohydrohalide having its halogen atom in one terminal cycle and having an olefinic linkage in the opposite terminal cycle.

2. An addition-rearrangement product oi. a hy-' drogen halide having a molecular weight above twenty and dicyclopentadiene, said product being formed in the presence or water and being a nordicyclopentadiene monohydrohalide having its halogen atom in one terminal cycle and having an oleflnic linkage in the opposite terminal cycle.

3. An addition-rearrangement product of hydrogen chloride and dicyclopentadiene, said product being formed in the presence of water and being a nordicyclopentadiene monohydrochloride having its chlorine atom in one terminal cycle and having an oleflnic linkage in the opposite terminal cycle.

4. An addition-rearrangement product of hydrogen bromide and dicyclopentadiene, said product being formed in the presence of water and being a nordicyclopentadiene monohydrobromide having its bromine atom in one terminal cycle and having an oleflnic linkage in the opposite terminal cycle.

ing a nordicyclopentadiene monohydroiodide having its iodine atom in one terminal cycle and having an olefinic linkage in the opposite terminal cycle.

6. A method for preparing norpolycyclopentadiene monohydrohalides having a halogen atom in one five-membered cycle and having an olefinic linkage in an opposite five-membered ring, which comprises reacting by addition and rearrangement in the presence of water and at temperatures up to about C. dicyclopentadiene and a hydrogen halide having a molecular weight above twenty.

8. A method for preparing nordicyclopentadiene monohydrochloride having its chlorine atom in one five-membered cycle and having an oleflnic linkage in an opposite five-membered ring, which comprises reacting by addition and rearrangement in the presence of water at temperatures up to about 110 C. dicyclopentadiene and hydrogen chloride.

9. A method for preparing nordicyclopentadiene monohydrobromide having its bromine atom in one five-membered cycle and having an oleiinic linkage in an opposite five-membered ring, which comprises reacting by addition and rearrangement in the presence of water at temperatures up to about 110 C. dicyclopentadiene and hydrogen bromide.

10. A method for preparing nordicyclopentadiene monohydroiodide having its iodine atom in one five-membered cycle and having an oleflnic linkage in an opposite flve-membered ring, which comprises reacting by addition and rearrangement in the presence of water at temperatures up to about 110 C. dicyclopentadiene and hydrogen iodide.

HERMAN A. BRUSON. 

